Crypto unit converters

Crypto denominations sit on top of each other in powers of 10: 1 ETH = 10⁹ Gwei = 10¹⁸ Wei; 1 BTC = 10⁸ Satoshi. Trivial arithmetic until you try to do it with JavaScript’s double-precision floats, which silently lose precision past 15-17 digits. The tools below use BigInt throughout so the math is exact at any scale.

The precision loss isn’t theoretical. A 1 ETH transaction stored as a JavaScript Number rounds the last two Wei digits to zero — invisible until your accounting reconciliation discovers 0.000000000000000018 ETH drift across a year of payments. The same trap catches gas estimates copy-pasted out of a block explorer (often quoted in Wei) and fed back into a transaction builder that expects Gwei or ETH. The Wei↔Gwei↔ETH converter here accepts and emits exact decimal strings, never floats — paste the value from your block explorer, pick the source unit, and the target unit is a copy-paste away with all 18 digits intact. For Bitcoin work, the Satoshi unit is the safe one to denominate in for storage and on-the-wire serialization; BTC is best reserved for the final presentation to humans. The conversion never silently truncates; fractional Satoshi (which shouldn’t exist) are surfaced as an input error.